The enactive account of cognition is the most mysterious strand of current thinking in this area. At its heart lie notions of embodiment, self-organisation, the environment and the proposition that we enact the world. As interesting as this is, enaction comes into its own when we discuss episodic memory, mental time travelling and niche creation. This chapter introduces the key ideas underpinning enaction and then illustrates their relevance to human-computer interaction. For example, when we recall the experiences offered by technology we rely on our episodic memories which provide us with a personal perspective. We do not just remember facts, we re-experience the events. This is an enactive perspective on memory. Similarly when we imagine how an item of technology might behave, it is likely that we are using our episodic memories to construct this. Finally, we construct niches – cognitive and technological – where we feel in control and safe and do so in a manner which is very similar to bringing forth (or enacting) the world. Enaction offers quite a different and very promising perspective on cognition and interactive technology.